The Sandcastle in Blackpool,England has just built some new waterslides, and they are brilliant.One of them is this
http://www.sandcastle-waterworld.co.uk/?OBH=528
This is the Sidewinder attraction, you start at the top of the drop,and go down the fairly steep vertical drop, and then you basiclly rock back and forth and finish at the bottom, Its short, but fun, and its the first slide of its kind in the world
They've also built a Masterblaster which they claim is the longest ever built(Not quite sure if thats really true, but it a lot longer than it looks)
http://www.sandcastle-waterworld.co.uk/masterblaster
The Ride contains 5 uphill sections, small tunnel sections,quite a few twists and turns, and a crazy finale that includes a double dip, basiclly coming off an uphill section,you go down a small drop only to go down a steeper drop straight afterwards creating in a huge splash at the bottom. It sort of shows it in the first picture in that link, obviously not very well, but you get the idea of it